Mangisi served as Chief Executive of ARM Platinum from February 2005 to May 2007 when he became Chief Executive of ARM Coal, a position he held until August 2012. Mangisi was Executive Director at ARM: Corporate Affairs until 30 June 2013. He has extensive experience in the fields of management, training, human resources, communications, corporate affairs and business development. Mangisi also has proven experience in leadership and mentorship. He has been a lecturer, as well as Chairman of various professional bodies and associations.